Tire recapping equipment



May 31, 1938. P. o. CHAMBERS I TIRE RECAPPING EQUIPMENT Filed Feb. 1'7, 1938 Perry QGhamberJ Gum/mm;

Patented May 31, 1938 UNITED STATES PATENT OFFICE" TIRE RECAPPING EQUIPMENT (5 Perry 0. Chambers, Chicago, Ill., assignor to Safety Vulcanizer Company,

Inc., Chicago,

111., a corporation of Illinois Application February 17, 1938, Serial No. 190,978

6 Claims.

This invention relates to tire re-capping equipment. 1

Heretofore, tire re-capping equipment has comprised a heated tread matrix designed to '5 cooperate only with the tread portion of the tire for vulcanizing new rubber onto said tread portion. Cold side-wall supporting rings have been associated with said tread matrix and spaced inwardly substantial distances therefrom. in This has exposed substantial surfaces of the tire sides between the side rings and the re-capping matrix to radiate heat therefrom for the purpose of confining the vulcanizing heat to the tread only.

Re-cappedtires have not heretofore been entirely satisfactory because of off-center and crooked treads. They are nearly all off-center from 1 to /2" in the direction of the bottom half of the re-capping vulcanizer. Many treads 20 are also wavy or snaky circumferentially about the tire.

Blowouts and separation occur'frequently in the circumferential areas on the sides of the tire which were exposed during the vulcanization.

.25 This isbelieved to be due to lack of restraining pressure on the outside of the tire permitting the rubber adjacent the tread to swell and become slightly porous during'the heating process and thus weakening the fabric structure at these 30 acreas.

By confining the heat to the tread the rubber does not soften and flow in adjacent areas of the tire sufficiently to permit suflicient realignment of the cords in the carcass whereby ;35 the tire will be effectively vulcanized in a mold different than the original without setting up conflicting stresses in the tire which may result in premature failure.

The general purpose of the present invention m n is to provide outwardly converging side-wall rings for use in a re-capping vulcanizer which extend closely adjacent the re-cappingmatrix and engage the side-walls adjacent the tread to force the tire to enter the matrix and to retain the .45 same properly centered therein during vulcan- 'iz'ation, whereby the re-capped treads will be in perfect alignment, the rubber in the side-walls will be prevented from swelling and weakening the carcass and the heat from the tread will .50 penetrate farther down the tire in gradually decreasing amount permitting a natural realignment of the cords in the tire and avoiding localized conflicting stresses.

The foregoing and other objects of the inven- 55 tion are attained in the re-capping vulcanizer illustrated in the accompanying drawing and described below. It is to be understood that the invention is not limited to'the specific form thereof shown and described.

Of the accompanying drawing, 5

Figure 1 is a radial section through a known type of re-capping vulcanizer with the improvement of the present invention incorporated therein.

Figure 2 is a radial section through the tread portion of a re-capped tire showing an off-center tread such as has been heretofore produced.

Figure 3 is a part radial section through a vulcanizer showing a modified formvof the invention.

Referring to the accompanying drawing, the numerals l and H indicate respectively upper and lower annular vulcanizer sections arranged to be heated in any suitable manner and removably receiving and retaining therein annular re-capping matrix sections l2 and I3 respectively, with or without a spacer ring l4 arranged between said matrix sections.

The matrix comprising parts I2, l3 and I4 is designed to embrace only the tread portion 2,5 of a tire from shoulder to shoulder as shown to vulcanize new rubber l5 onto the old rubber l6 of a tire [7. During a vuleanizing operation tire I1 is mounted on a rim i8 with a pressure bag,

or tube I9 therein which is expanded by internal fluid pressure after the tire i1 is placed into the vulcanizer as shown to force the new tread rubber l5 into the recesses in the matrix.

The vulcanizer of the type shown has usually utilized side wall rings 20, 20 but nevertheless such vulcanizers have produced off-center treads such as shown in Figure 2 and tires with the other defects noted in the opening paragraphs of this specification. I

To obviate these deflects, rings 2|, 2| are pro- 40 vided which extend closely adjacent the tread matrix but out of contact therewith whereby effective re-capping vulcanization is secured of the new rubber i5 to the old rubber I6 with the new tread perfectly centered, but with sufficient pressure being maintained on the sidewalls of the tire adjacent the tread to avoid swelling of the rubber and weakening of the carcass and also with suflicient penetration of heat to the carcass, tapering away from the tread, of course, to permit such realignment of cords in the carcass as to avoid localized conflicting stresses. The spacing of the centering rings 2| from the tread matrix provides gaps G. G. which result in the centering rings being for supporting the same on radial webs 22 inside of the skirt portions l and II or the Vul- A- modified V treadecen'tering 1 ring is shown at 25' in Figure 3 which'has a por canizer sections.

"tion 25 'similarjtoportion ZIP of ring 2| "and'a portion 25? embracing the tread, matrix, but

'not' contacting thesameduring vulcanization,

"fside-ywalls against-swellingfand prevent porosity therein and to cause effective cord realignment,

pressure in the tire.

The use of the above-described vulcanizer will be understood by'skilled artisans; Therings 2! or will be retained in the vulcanizersections assembled with the tread matrix and the :rings' 20 and'williserve to hold, the tread of the tire properly centeredin the matrix to' confine the Modifications fithe inventionotherthan those 7 disclosed h'erei'n'may be 'resorted to without departing-from the: spirit thereof or the scope of V thea'ppended claims. a a a swim is claimed is:

cooperating 1vulcanizer sections, means for supportingyand inflating a tire therein, a tread matrix supported in said sections for embracing the tread rubber only of a tire therein,'means .for heating said tread matrix, side-wall supporting plates associated with said vulcanizer a substantial, distance inwardly of the tread matrix and outwa'rdlyr converging plates for engaging the side-walls of the tire adjacent the tread and be tweenthe side-wall plates and the tread matrix for centering a'tire tread in said matrix and supporting it against, cit-center movement ,untila new tread is' vulcanized on the tire, there being gaps of such width-between 'the tread matrix and the centering plates as'to result in 'the latter being ofless temperaturbut preventing bulging of the tire therebetween.

2. 'Ajvulcanizer ior rtecapping tires, comprising cooperating'vulcanizer' sections, means for sup- 7 porting and inflating a tire therein, a tread' matrixsupported insaid sections forembracing the tread rubber only of apti're therein, means for heating said tread matrix, side-wall support- 7 ing plates associated with said vulcanizer 'a sub,-

stantial distance inwardly of the tread matrix and outwardly converging plates for engaging the "side-walls of the tire adjacent the tread and between the side-wall plates and theitread matrix for centeringa tire 'tread'in said matrix and supporting it against ofi-centenmovement until a 'fnew tread is vulcanizedfonthe tire, said vulcanizer. sections having inwardly extending skirts,

'means for retaining said side-wall plates in said iskirtsfand means for retaining said centering plates between the side-wall plates and the tread matrix, there being gaps 7 between the centering 1"; :A'vulcanizer Ior re-capping tires, comprising Q will soften the rubber adjacent the tread to relieve'localized stresses adjacent the tread.

3. A vulcanizer forre-capping tires, comprising cooperating vulcanizer sections, means for supporting and inflating a. tire therein, a tread matrix supported in said sections forembracing the tread rubber only of a tire therein, means for applying heat to said tread matrix, side-wall supporting plates associated with said vulcanizer,

a substantial distance inwardly of the tread matrix "and outwardly converging plates between the side-wall supporting plates and. the matrix 7 1 fox-engaging the side-walls of the tire" adjacent 1 V 7 the tread between the side-wall plates and the being held in spaced relation by the internal tread matrix for centering a tire tread'insald matrix and supporting it againstofi-centrmove merit until'a new tread is vulcanized on the tire,

and the matrix of such width as to prevent bulging'of the tire therebetween, but resulting in application of a lower, temperature to nthe tire there being gaps, between thecentering plates tread matrix.

'4. A tire re-capping vulcanizer including eo- 25 operating annular vulcanizer sections, means for supporting and inflating a tirethereima tread matrix carried thereby'for engaging the tread rubber only of a tire' to be re-capped," means to;.

apply heat to saidrtread matrix, and outwa'rdly' converging side-wall engaging i'plates' supported in said vulcanizer out of contact with but closely,

adjacentsaid matrix 1for centering, and holding centered, .a tire; to be re-capped in said vulcanizer centering plates and the matrix.

'5. A tire re-capping vulcanizerincluding co- Without permitting the tire to bulge between the operating annular vulcanizer sections, vmeans 'for supporting and inflatinga tire therein, a tread matrix carriedtherebyior engaging the tread rubber only of la tireto-be re-capped, means to i a ply heat to said tread matrix, and outwardly converging side-walLen'gaging plates supp rted in said vulcanizerout of contact withbut closely adjacent. said matrix for centering, andholding centered, a tire to be-re -cappedin said vulcanizen gthere being gaps betweenthe' tread matrixi and- "the converging side-wall engaging plates of such widthas toprevent bulging of a tire therebetwen but resulting, inv application 'of a lower temperature to.the tire inwardly of 'the gaps than that 1- applied to the'tire by the tread matrix,

6. .Thecombination'in'a horizontal annular tire re-capping vulcanizer of a tread matrix for em bracing the tread rubber only of a tire therein,

' means for applying'heat to said tread matrix,

means for'supporting and inflating atire therein, and side-wall engaging plates adjacent said tread matrix converging outwardly substantially to-the contour oftheouter portions of the side-walls. of saidtire for centering ,a' tirezre specting said 1 matrix and against which side-wall engaging ''plates the tireis inflated during vulcanizatlonjf there being gaps betwee'n said, sidewall engaging 7 plates and said tread'matrix of such width as" to prevent bulging of a tire therebetween and'caus ing said centering plates to beef, substantially less temperature than the tread matrix, butyet sufliciently hot to cause some softenlngrof' the rubberof the tire adjacent the tread to permit readjustment in the carcass newly applied tread, r 1 PERRY oormMnEas.

or the tire to, the 7. 

